Philosophy of Mind

A Contemporary Introduction

John Heil

• Publisher: Routledge
• Year: 2019
• ISBN:
  9780429015984
• Edition: 4
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

The book is intended as a reader-friendly introduction to issues in the philosophy of mind, including mental–physical causal interaction, computational models of thought, the relation minds bear to brains, and assorted -isms: behaviorism, dualism, eliminativism, emergentism, functionalism, materialism, neutral monism, and panpsychism. The Fourth Edition reintroduces a chapter on Donald Davidson and a discussion of 'Non-Cartesian Dualism', along with a wholly new chapter on emergence and panpsychism. A concluding chapter draws together material in earlier chapters and offers what the author regards as a plausible account of the mind's place in nature. Suggested readings at the conclusion of each chapter have been updated, with a focus on accessible, non-technical material.

Key Features of the Fourth Edition

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• Includes a new chapter, 'Emergence and Panpsychism' (Chapter 13), reflecting growing interest in these areas

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• Reintroduces and updates a chapter on Donald Davidson, 'Radical Interpretation' (Chapter 8), which was excised from the previous edition

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• Updates 'Descartes' Legacy' (Chapter 3) to include a discussion of E. J. Lowe's arresting 'Non-Cartesian Dualism', also removed from the previous edition

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• Includes a highly revised final chapter, which draws together much of the previous material and sketches a plausible account of the mind's place in nature

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• Updated 'Suggested Reading' lists at the end of each chapter

1
Introduction

1.1 Appearance and Reality

Does a tree falling in the forest make a sound when no one is around to hear it? The question is familiar to every undergraduate. One natural response is that of course the tree makes a sound—why shouldn’t it? The tree makes a sound whether anyone is on hand to hear it or not. And, in any case, even if there are no people nearby, there are rabbits, birds, or at the very least insects that would hear it crashing down.

Consider a more measured response, versions of which have percolated down through successive generations of student philosophers. The tree’s falling creates sound waves that radiate outwards as do ripples on the surface of a pond, but in a spherical pattern. If these sound waves are intercepted by a human ear—or maybe, although this might be slightly more controversial, the ear of some nonhuman sentient creature—they are heard as a crashing noise. Eventually the sound waves, detected or not, peter out.

Whether an unobserved falling tree makes a sound, then, depends on what you mean by sound. If you mean ‘heard noise’, then (rabbits and birds aside) the tree falls silently. If, in contrast, you mean something like ‘distinctive spherical pattern of impact waves in the air’, then, yes, the tree’s falling does make a sound.

Most people who answer the question this way consider the issue settled. The puzzle is solved simply by getting clear on what you mean when you talk about sounds. Indeed, you could appreciate the original question as posing a puzzle only if you were already prepared to distinguish two senses of ‘sound’. But what precisely are these two senses? On the one hand, there is the physical sound, a spherical pattern of impact waves open to public inspection and measurement—at any rate, open to public inspection given the right equipment. On the other hand, there is the experienced sound. The experienced sound depends on the presence of an observer. It is not, or not obviously, a public occurrence: although a sound can be experienced by many people, each observer’s experience is ‘private’. You can observe and measure subjects’ responses to experienced sounds, but you cannot measure the experiences themselves. This way of thinking about sounds applies quite generally. It applies, for instance, to the looks of objects, to their tastes, their smells, and to ways they feel to the touch. Physicist Erwin Schrödinger put it this way in discussing sensations of color.

The sensation of colour cannot be accounted for by the physicist’s objective picture of light-waves. Could the physiologist account for it, if he had fuller knowledge than he has of the processes in the retina and the nervous processes set up by them in the optical nerve bundles and in the brain? I do not think so.

(Schrödinger 1958, 90)

The picture of the universe and our place in it that lies behind such reflections has the effect of bifurcating reality. You have, on the one hand, the ‘outer’ material world, the world of trees, forests, sound waves, and light radiation. On the other hand, you have the ‘inner’ mental world: the mind and its contents. The mental world includes conscious experiences: the looks of seen objects, ways objects feel, heard sounds, tasted tastes, smelled smells. The ‘external’ material world comprises the objects themselves, and their properties. These properties include such things as objects’ masses and spatial characteristics (their shapes, sizes, surface textures, and, if you consider objects over time, motions and changes in their spatial characteristics).

Following a long tradition, you might call those observed qualities properly belonging to material objects ‘primary qualities’. The rest, the ‘secondary qualities’, are characteristics of objects (presumably nothing more than arrangements of objects’ primary qualities) that elicit certain familiar kinds of experience in conscious observers. Experience reliably mirrors the primary qualities of objects. Secondary qualities, in contrast, call for a distinction between the way objects are experienced, the way they appear, and the way they are. This distinction shows itself in student reflections on trees falling in forests. More fundamentally, the distinction encourages us to view conscious experiences as occurring ‘outside’ the material universe.

You might doubt this, confident that conscious experiences occur in brains, and regarding brains as respectable material objects. But now apply the distinction between primary and secondary qualities to brains. Brains—yours included—have assorted primary qualities. Your brain has a definite size, shape, mass, and spatial location; it is made up of particles, each with a definite size, shape, mass, and spatial location, and each of which contributes in a small way to the brain’s overall material character. In virtue of this overall character, your brain would look (and presumably sound, smell, feel, and taste!) a particular way. This is just to say that your brain could be variously experienced. The qualities of these experiences, although undoubtedly related in some systematic way to the material reality that elicits them, apparently differ from qualities possessed by any material object, including your brain. But if that is so, where do we situate the qualities of experience, the appearances?

Your first instinct was to locate them in the brain. But inspection of brains reveals only familiar material qualities. An examination of a brain—even with the kinds of sophisticated instrumentation found in the laboratory of the neurophysiologist and the neural anatomist—reveals no looks, feels, heard sounds. Imagine that you are attending a performance of Die Walküre at Bayreuth. Your senses are assaulted by sounds, colors, smells, even tastes. A neuroscientist observing your brain while all this is occurring would observe a panoply of neurological activities. But you can rest assured that the neuroscientist will not observe anything resembling the qualities of your conscious experience.

The idea that these qualities reside in your brain, so natural at first, appears, on further reflection, unpromising. But now, if qualities of your experiences are not found in your brain, where are they? The traditional answer, and the answer that we seem driven to accept, is that they are located in your mind. And this implies, quite straightforwardly, that your mind is somehow distinct from your brain. Indeed, it implies that the mind is not a material object at all, not an entity on all fours with tables, trees, stones—and brains! Minds appear to be non material entities: entities with properties not possessed by brains, or perhaps by any material object. Minds bear intimate relations to material objects, perhaps, and especially intimate relations to brains. Your conscious experiences of ordinary material objects (including your own body) appear to reach you ‘through’ your brain; and effects of your conscious deliberations have on the universe (as when you decide to turn a page in this book and subsequently turn the page) require the brain as an intermediary. Nevertheless, the conclusion seems inescapable: the mind could not itself be a material object.

1.2 The Unavoidability of the Philosophy of Mind

You might find this conclusion unacceptable. If you do, I invite you to go back over the reasoning that led up to it and figure out where that reasoning went off the rails. In so doing, you would be engaging in philosophical reflection on the mind: philosophy of mind. Your attention would be turned, not to the latest findings in psychology or neuroscience, but to commonsense assumptions with which this chapter began and to a very natural line of argument leading from these assumptions to a particular conclusion. As you begin your reflections, you might suspect a trick. If you are right, your excursion into philosophy of mind will be brief. You need only locate the point at which the trick occurs.

I think it unlikely that you will discover any such trick. Instead you will be forced to do what philosophers since at least the time of Descartes (1596–1650) have been obliged to do. You will be forced to choose from among a variety of possibilities, each with its own distinctive advantages and liabilities. You might, for instance, simply accept the conclusion as Descartes did: minds and material objects are distinct kinds of entity, distinct ‘substances’. You might instead challenge one or more of the assumptions that led to that conclusion. If you elect this course, however, you should be aware that giving up or modifying an assumption can have unexpected and possibly unwelcome repercussions elsewhere. In any case, you will have your work cut out for you. The best minds in philosophy—and many of the best outside philosophy, as well—have turned their attention to these issues, and there remains a notable lack of anything resembling a definitive, uncontested view of the mind’s place in the universe.

Do not conclude from this that it would be a waste of time for you to delve into the philosophy of mind. On the contrary, you can enjoy the advantage of hindsight. You can learn from the successes and failures of others. Even if you cannot resolve every puzzle, you might at least come to learn something important about your own picture of the universe and your place in it. If you are honest, you will be obliged to admit that this picture is gappy and unsatisfying in many respects. This, I submit, represents an important stage for each of us in coming to terms with ourselves and our standing in the order of things.

1.3 Science and Metaphysics

Some readers will be impatient with all this. Everyone knows that philosophers only pose problems and never solve them. Solutions to the important puzzles reside with the sciences, so it is to science that we should turn if we are ever to understand the mind and its place in a universe of quarks, leptons, and fields. Residual problems, problems not susceptible to scientific resolution, are at bottom phony pseudo-problems. Answers you give to them make no difference; any ‘solution’ you care to offer is as good as any other.

Although understandable, this kind of reaction is ill-considered. The success of science has depended on the enforcement of well-defined divisions of labor coupled with a strategy of divide and conquer. Consider: there is no such subject as science per se, there are only individual sciences—physics, chemistry, meteorology, geology, biology, psychology, sociology. Each of these sciences (and of course there are others) carves off a strictly circumscribed domain. Staking out a domain requires delimiting permissible questions. No science sets out to answer every question, not even every ‘empirical’ question. In this way, every science passes the buck.

The practice of buck-passing is benign because, in most cases, the buck is passed eventually to a science where it stops. Sometimes, however, the buck is passed out of the sciences altogether. Indeed, this is inevitable. The sciences do not speak with a single voice. Even if every science were fully successful within its domain of application, we should still be left with the question of how these domains are related, how pronouncements of the several sciences are to be calibrated against one another. And this question is, quite clearly, not a question answerable from within any particular science.

Enter metaphysics. One traditional function of metaphysics—or, more particularly, that branch of metaphysics called ontology—is to provide a completely general, overall conception of how things are. This includes, not the pursuit of particular scientific ends, but an accommodation of the pronouncements of the several sciences. It includes, as well, an attempt to reconcile the sciences with ordinary experience. In one respect, every science takes ordinary experience for granted. A science is ‘empirical’ insofar as it appeals to observation in confirming experimental outcomes. But the intrinsic character of observation itself (and, by extension, the character of observers) is apparently left untouched by the sciences. The nature of observation—outwardly directed conscious experience—stands at the limits of science. It is just at this point that the puzzle with which this chapter began rears its head.

Scientific practice presupposes observers and observations. In the end, however, the sciences are silent about the intrinsic nature of both. The buck is passed. Our best hope for a unified picture, a picture that includes the universe as described by the sciences and includes, as well, observers and their observations, lies in pursuing metaphysics and, in particular, serious ontology. The buck stops here. You can, of course, turn your back on the metaphysical issues. This, however, is easier said than done. Often those who most loudly proclaim their independence from philosophical influences in fact embrace unacknowledged metaphysical assumptions. In considering the nature of the mind, the question is not whether you are going to engage in metaphysical thinking, but whether you are going to do so honestly and self-consciously.

1.4 Metaphysics and Cognitive Science

This book concerns the metaphysics—the ontology—of mind. It revolves around reflections on questions about mind that fall partly or wholly outside the purview of the sciences. I should warn you that this is not a fashionable or glamorous endeavor. Many philosophers regard metaphysics as sterile and dated. Many more have arrived at the belief that our best bet for understanding the mind and its place in the universe is to turn our backs on philosophy altogether. These philosophers promote the idea that the philosophy of mind is, or ought to be, one component of what has come to be called cognitive science. Cognitive science includes elements of psychology, neuroscience, computer science, linguistics, and anthropology. What has a philosopher to offer the scientists who work in these areas? That is a good question.

Perhaps philosophers can provide some kind of unifying influence, a general picture that accommodates finer-grained assessments issuing from the scientific contributors to cognitive science. This, it would seem, is simply to engage in a kind of attenuated metaphysics. The metaphysics is attenuated to the extent that it excludes traditional ontological concerns, and excludes as well consideration of the relation sciences such as physics or chemistry bear on our uncovering the nature of the mind.

If I sound skeptical about attempts to assimilate the philosophy of mind to cognitive science, I am. This book is premised on the conviction that the philosophy of mind is continuous with metaphysics as traditionally conceived. The difficult questions that arise in the philosophy of mind—and some would say the difficult questions tout court—are at bottom metaphysical questions. Such questions are, to all appearances, both legitimate and unavoidable. More to the point, philosophers can make (and in fact have made) progress in addressing them. This does not mean that philosophers have at hand a catalogue of fully satisfactory answers that could be succinctly reviewed and assessed in an introduction to the philosophy of mind. It does mean that you can reasonably hope to find, in subsequent chapters, some help in sorting through and eliminating what at fi...